TOKYO, Jan. 26 (Xinhua) -- The Japanese currency yen surged to the 154 level against the U.S. dollar in early trading Monday.

The yen jumped by nearly 4 yen to the lower 154 zone against the dollar in early Monday trading, from about 158.4 at the close of trading in the Tokyo foreign exchange market on Jan. 23.

While authorities in Tokyo declined to comment on the yen's sharp appreciation, Nikkei Asia and other media outlets reported that the New York Federal Reserve had conducted a "rate check" with major banks last Friday, citing sources familiar with the issue.

Rate checks are when currency authorities ask financial institutions what price they would quote in the event of an intervention, Nikkei Asia reported, noting that the move stops short of an actual intervention but sends a stronger signal than public comments on exchange rates.

This suggested the possibility that the United States and Japan were working together to stop the yen from weakening, the report said.